1. Field of the Invention
The present invention relates to a method of manufacturing a device, for dividing a wafer in which devices are formed respectively in a plurality of regions demarcated by planned dividing lines formed in a grid pattern in the face-side surface of the wafer, along the planned dividing lines into individual devices, and attaching a die-bonding adhesive film to the back-side surface of each of the devices.
2. Description of the Related Art
For example, in the semiconductor device manufacturing process, devices such as ICs and LSIs are formed in a plurality of regions demarcated by streets (planned dividing lines) formed in a grid pattern in the face-side surface of a roughly circular disk-shaped semiconductor wafer, and the regions provided respectively with the devices are split from each other, to manufacture the individual devices. As a dividing apparatus for dividing the semiconductor wafer, a cutting apparatus generally called dicing apparatus is used. The cutting apparatus is so designed as to cut the semiconductor wafer along the planned dividing lines by a cutting blade having a thickness of about 40 μm. The devices thus split from each other are packaged, to be widely utilized for electric apparatuses such as mobile phones and personal computers.
Each of the individually divided devices has a die-bonding adhesive film, called a die attach film formed from an epoxy resin or the like and having a thickness of 70 to 80 μm, attached to the back-side surface thereof, and is bonded to a device-supporting die bonding frame through the adhesive film by heating. As a method for attaching the die-bonding adhesive film to the back-side surface of the device, a method is ordinarily used in which the adhesive film is adhered to the back-side surface of the semiconductor wafer, the semiconductor wafer is adhered to a dicing tape through the adhesive film, and then the adhesive film is cut together with the semiconductor wafer by the cutting blade along the planned dividing lines formed in the face-side surface of the semiconductor wafer, thereby producing the devices each having the adhesive film attached to the back-side surface thereof (refer to, for example, Japanese Patent Laid-open No. 2000-182995).
Meanwhile, in the method of cutting the adhesive film together with the semiconductor wafer by the cutting blade, the devices would not be damaged even when the adhesive film is cut together with the semiconductor wafer if the thickness of the wafer is large (for example, 500 μm or more). However, where the thickness of the semiconductor wafer is small (for example, 200 μm or less), the adhesive film being in a paste-like state leads to the problem that the semiconductor wafer shows irregular motions during cutting, whereby chipping is generated at side surfaces (cut surfaces) of the devices, and the device quality deteriorates accordingly. In addition, when the adhesive film is cut together with the semiconductor wafer by a cutting blade, cuttings of the adhesive film may be formed in a whisker-like form, to adhere to a bonding pad provided on the device.
Besides, since the knife edge of the cutting blade is formed by consolidating diamond abrasive grains with plating, cutting the adhesive film by the cutting blade leads to clogging at the knife edge, so that frequent dressing is needed, and the life of the cutting blade is decreased accordingly. Incidentally, in order to solve the above-mentioned problem, it may be contemplated to adopt a method in which only the semiconductor wafer is cut by a cutting blade into individual devices, and thereafter the dicing tape to which the adhesive film attached to the back-side surface of the semiconductor wafer is adhered is expanded, thereby breaking the adhesive film along the individual devices. However, the broken surfaces of the adhesive film may become wavy due to the width of the cutting grooves formed in the semiconductor wafer by the cutting blade, and the adhesive film may be separated unevenly, making it difficult to secure a stable device quality.